1. Field of the Invention
The present invention relates to an electromagnetic induced accelerator and, more particularly, to an electromagnetic induced accelerator using one single strand of coil to accomplish the purposes of generating plasma, inducing a magnetic field and secondary current and accelerating movement of plasma, respectively, or using a strand of coil to accomplish all of the purposes.
2. Description of the Related Art
An electromagnetic induced accelerator, or a plasma accelerator, operates to accelerate movement of plasma existing or generated in a spatial portion by electric and magnetic energy.
In the early stage, a plasma accelerator was developed for an ion engine of a rocket for long-distance space travel and nuclear fusion, but it has been used for a wafer etching technique in a semiconductor manufacturing process.
Plasma is the gaseous state of hot ionized material consisting of negatively charged electrons and positively charged ions with approximately equal concentrations of both, so that the total gas is in approximately charge neutral. Therefore, it is called the fourth state of matter besides the three states of matter-solid, liquid and gas.
As the temperature rises, most of all matter changes from a solid state, to a liquid state and then to gas state in turns. At several ten thousands of degrees (° C.), a gas splits into electrons and atomic nucleuses, resulting in a plasma state.
FIG. 1 is a cut-away perspective view of an electromagnetic induced accelerator in accordance with the related art.
With reference to FIG. 1, an electromagnetic induced accelerator comprises inner and outer circular loop coils 10, 20, a channel 40 contacting the inner circular loop coils 10 on its internal portion and outer circular loop coils 20 on its external portion, an outer cylinder 30, an inner cylinder 60 and a discharging coil 50 disposed underneath the channel 40.
The inner and outer loop coils 10, 20 are arranged coaxially in parallel to each other, and a current is applied to the coils 10, 20 circumferentially around the channel 40. A current is applied to the coils 10, 20 in the same direction, clockwise or counter-clockwise and this induces a magnetic field across the channel 40. In electromagnetic induced accelerators in accordance with the related art, inner and outer loop coils comprise a plurality of coils, respectively, and the coils 10, 20 are provided to gradually diminish the magnetic field induced in the channel 40 in the axial direction by reducing current flowing through each coil winding around in the axis direction. The magnetic field is induced across the channel 40 to be perpendicular to the axial direction and gradually decreases along the axial direction.
The magnetic field induced in the channel induces a secondary current in accordance with Maxwell's equation. Plasma generated in the channel 40 by the discharging coil 50 accelerates in the axial direction toward an exit 70 by the magnetic field induced across the channel 40 and the secondary current.
Such an electromagnetic induced accelerator in accordance with the related art is based on a B-field modulation method which accelerates plasma by causing a difference in magnetic pressure between the entrance side 80 and the exit 70 of the channel by applying large current and small current to the loop coils winding around the entrance side 80 and the exit side 70, respectively.
Accordingly, such B-field modulation requires a plurality of inner loop coils 10 installed in the inner cylinder 60 to independently apply different driving currents to each inner loop coil 10. It means that a plurality of pull-in wires for the inner loop coils 10 should be externally pulled in the inner cylinder 60. Accordingly, the number of the inner loop coils 10 to wind around the internal surface of the inner cylinder 60 is limited in case that the inner cylinder 60 is small in diameter. Further, influence of the pull-in wires to the magnetic field induced by the coils is so high. As a result, it is hard to induce the magnetic field as designed due to the coupling noises of the coils.